CMMG Resolute MK4 338 ARC 16.1" Upper Receiver
- CMMG Resolute MK4 22 ARC 16.1" Rifle $823.06
- CMMG Resolute MK4 22 ARC 16.1" Rifle $831.38
- CMMG Resolute MK4 22 ARC 16.1" Rifle $831.38
- 22LR, 16.1" Barrel $693.08
- 300 AAC 14.5" Pinned Upper $482.29
- 300 Blackout, 16.1" $482.29
- 300 Blackout, 16.1" Barrel $823.06
- 350 Legend, 16.1" Barrel $831.38
- 5.56 16.1" Upper $823.06
- 5.56 NATO 16.1" Upper $498.07
- 6.5 Grendel 16.1" $823.06
- 6mm ARC 16.1" Upper $925.94
CMMG Resolute MK4 upper receiver in 338 ARC with 16.1" black nitride barrel, aluminum receiver with black Armor Cerakote finish. AR15-compatible platform delivers superior stopping power with less gas tuning.
Fits: AR15
The CMMG Resolute MK4: Modern Power in the AR15 Platform
The CMMG Resolute MK4 upper receiver brings the proven reliability of the AR15 platform together with the substantial stopping power of the 338 ARC cartridge. This is a purpose-built upper designed for shooters who demand more energy downrange without the complexity of extensive tuning.
Why 338 ARC?
The 338 ARC cartridge represents a thoughtful evolution in intermediate rifle design. It delivers the versatility of subsonic and supersonic performance—much like the popular 300 Blackout—but with greater energy transfer to the target and less finicky gas system adjustment when switching between suppressed and unsuppressed configurations.
Key Features
- Caliber: 338 ARC
- Barrel Length: 16.1 inches
- Barrel Finish: Black nitride for durability and corrosion resistance
- Receiver Material: Aluminum with black Armor Cerakote coating
- Twist Rate: 1:8 for optimal performance with traditional .338 projectile construction
- Bolt Compatibility: Uses the same bolt as 6.5 Grendel AR15s, maximizing parts interchangeability
Platform Compatibility
This upper receiver integrates seamlessly with standard AR15 lower receivers, making it an excellent choice for builders and those looking to expand their platform capabilities. The 338 ARC's design philosophy prioritizes parts compatibility without sacrificing performance.
A Practical Choice
Whether you're building a dedicated hunting rifle, a precision intermediate-range system, or exploring the capabilities of modern intermediate cartridges, the CMMG Resolute MK4 delivers straightforward, reliable performance.
